public class IM_EasyCalc {

  public class additionInput {
    @invocableVariable(Required = true Label = 'First Number' Description = 'First number to add')
    public Integer first;
    @invocableVariable(Required = true Label = 'Second Number' Description = 'Second number to add')
    public Integer second;
  }

  public class additionResult {
    @invocableVariable
    public Integer result;
    public AdditionResult(Integer a, Integer b) {
      this.result = a + b;
    }
  }

  @invocableMethod(Label = 'Add' Description = 'Add Two Numbers')
  public static List<AdditionResult> addTwoNumbers(List<AdditionInput> requests) {
    List<AdditionResult> results = new List<AdditionResult>();
    for (AdditionInput request : requests) {
      results.add(new AdditionResult(request.first, request.second));
    }
    return results;
  }
}
